Seal
L-sealer
Creates the seal around individual products or grouped packs using suitable shrink film.
View related machineryL-seal lines
L-sealer and shrink tunnel lines
An L-sealer and shrink tunnel line is a common route for neat retail presentation packs, boxed goods and printed products.
UK specification advice
For clean all-round shrink presentation
The L-sealer creates a two-sided seal around the pack before the product passes through the heat tunnel, where the film shrinks around the product.
This route is often used when the finished pack needs a clean appearance rather than open-sided transit bundling.
The correct system depends on the largest product, the required output, operator loading method and film type.
Machinery route
L-sealer line components
A good result depends on the sealer, film and tunnel working together.
Shrink
Shrink tunnel
Applies controlled heat and airflow to recover the film around the product.
View related machineryFilm
POF film route
Often selected for presentation packs because it can give a clean and clear finish.
View related machineryBuying notes
L-sealer line notes
When comparing L-sealer and shrink tunnel lines, check the maximum pack dimensions and allow enough clearance for the film sleeve as well as the product.
Tunnel length, temperature and conveyor speed affect the finish. A short or undersized tunnel can leave loose film or uneven corners.
Operator loading should be considered early. For variable products, an easy-loading semi-automatic line may be more practical than a higher speed automated line.
Common questions
L-sealer and tunnel FAQs
What is an L-sealer used for?
An L-sealer is used to seal shrink film around individual products or packs before heat shrinking.
Is an L-sealer better than a chamber sealer?
It depends on output and pack size. Chamber sealers are compact, while L-sealer and tunnel lines suit higher throughput and larger packs.
What film is used with L-sealers?
POF is common for many presentation packs, though the final choice depends on product and finish.
Can L-sealer lines be semi-automatic?
Yes. Many L-sealer and tunnel systems use operator loading with automatic sealing and conveyor transfer.
Next step
Ask Lancing to recommend a shrink wrapping route
Send product dimensions, pack format, approximate output rate and film preference. Lancing can help compare chamber sealers, L-sealers, sleeve sealers, heat tunnels and complete shrink wrapping lines.
Complete L-seal route
Balance sealing, transfer, tunnel and cooling as one line
An L-sealer and heat tunnel should be specified as one production process. The accepted line rate is governed by product presentation, seal formation, tunnel dwell, thermal loading and post-tunnel handling together.
Coordinate seal cycle and tunnel dwell
The sealer must present packs at a rate and spacing the tunnel can process within its approved thermal window. A faster seal cycle is not useful when product spacing, tunnel dwell or cooling becomes the constraint.
Design transfers around loose film
The pack is vulnerable between sealing and shrink. Conveyor gaps, guides and product orientation should avoid dragging, puncturing or moving the loose film before it enters stable airflow.
Retain cooling and inspection space
Allow the film to settle before close guidance, accumulation, labelling or case packing. Position inspection where seals, corners and product condition can be assessed without disrupting the line.
Line information required
- Largest and smallest loose-film envelope and complete product weight.
- Production film code, gauge, width/fold and perforation.
- Manual or automatic infeed method and expected pack spacing.
- Required sustained good-pack output and normal production gaps.
- Tunnel aperture, conveyor support, airflow control and cooling distance.
- Downstream machine, accumulation, scanning and handling constraints.
Application review
Define the complete L-seal and tunnel duty
Send representative products, production film, required pack finish, sustained output and the full infeed/outfeed layout so the line can be sized and trialled as one process.